By Dr. Mercola
Do you want to live to be at least 100 like I do? This is quite achievable today, but living that long loses much of its appeal if you aren't healthy for the duration.
One excellent tool for increasing both health AND longevity is intermittent fasting, i.e. an eating schedule in which you feast on some days and dramatically cut your consumption on others.
One of the downsides to the modern Western lifestyle is eating too frequently, which makes your body lazy about performing its repair and rejuvenation operations. Intermittent fasting effectively mimics the eating habits of our ancestors, who did not have access to grocery stores or food around the clock.
They cycled through periods of feast and famine, and modern research shows this cycling imparts a number of health benefits, such as improved cardiovascular health, better metabolic function, and reduced cancer risk.
If the very thought of fasting makes you shudder with anxiety, then you're in luck! EFT (emotional freedom technique) practitioner Julie Schiffman has a great video for reducing your anxiety about fasting.
EFT is a powerful energy psychology tool that has helped hundreds of thousands overcome emotional challenges. It uses acupuncture meridians to help neutralize electrical brain disturbances that emotional wounding can cause.
I strongly recommend tapping along with her if you have any hesitation at all about fasting. Being in the right mindset is 90 percent of the challenge, and EFT is a highly effective tool toward that end.
Intermittent Fasting Rejuvenates Your Blood and Immune System
A study published in Cell Stem Cell1 discovered that intermittent fasting causes your body to beef up your immune system by getting rid of damaged white blood cells and replacing them with new ones, shifting stem cells from a dormant state to a state of self-renewal. Fasting essentially hits your body's "reset button."
Researchers from the University of Southern California found that during prolonged fasting, your white blood count drops, but when you resume eating, this count goes up.
Upon investigating this phenomenon, researchers found that people's bodies were purging out the old, damaged immune cells, and then replacing them with new ones.
The fasting cycle appears to flip on a "regenerative switch," triggering a key gene controlling the enzyme PKA. During fasting PKA is reduced, which flips on this regenerative switch that sends your body's stem cells into action.
The scientists believe their findings have major implications for healthier aging and are investigating the possibility that these benefits are applicable to many different systems and organs, beyond your immune system. The study's coauthor Valter Longo said:2
"We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system."
Fasting Is Good for Your Heart, Brain and Waistline
Fasting is commonplace throughout history and has been used as part of various spiritual practices for millennia. But modern science now tells us that fasting actually offers a number of health benefits, including the following:
• Normalizing your insulin and leptin sensitivity, and boosting mitochondrial energy efficiency: One of the primary mechanisms making intermittent fasting so beneficial for your health is related to its impact on insulin and leptin sensitivity. While sugar is a source of energy for your body, it also causes insulin/leptin resistance when consumed excessively.
Insulin/leptin resistance, in turn, is a primary driver of chronic disease—from heart disease to type 2 diabetes to cancer. Intermittent fasting helps retrain your body to use fat as its primary fuel.
Mounting evidence confirms that when your body becomes adapted to burning fat instead of sugar, your disease risk dramatically drops. Fasting also normalizes ghrelin levels, known as "the hunger hormone." Another boon of intermittent fasting is that it helps eliminate sugar cravings.
• Promoting human growth hormone production (HGH): Research has shown that fasting can raise HGH by as much as 1,300 percent in women, and 2,000 percent in men.3 HGH plays an important part in health, fitness, and slowing the aging process. It's also a fat-burning hormone, which helps explain why fasting is so conducive to weight loss.
• Lowering triglyceride levels and improving other biomarkers of disease.
• Reducing oxidative stress: Fasting decreases the accumulation of oxidative radicals in the cell, thereby reducing oxidative damage to cellular proteins, lipids, and nucleic acids associated with aging and disease.
• Protects your brain: Fasting boosts the production of a protein called brain-derived neurotrophic factor (BDNF), stimulating the release of new brain cells and triggering numerous other chemicals that protect you from the changes associated with Alzheimer's and Parkinson's disease.
Research suggests alternate-day fasting (restricting your meals on fasting days to about 600 calories), can boost BDNF by 50 to 400 percent, depending on the region of the brain.4
Animal research shows that fasting has a beneficial impact on longevity by several mechanisms, including improved insulin sensitivity and inhibition of the mTOR pathway. Intermittent fasting is also one of the most effective ways to shed unwanted fat. When your body doesn't need sugar as its primary fuel, you'll experience fewer cravings when your sugar stores run low.
Some warn that intermittent fasting may result in loss of lean body mass,5 but I have not found this to be true. Dr. Krista Varaday, assistant professor of Kinesiology and Nutrition at the University of Illinois, has conducted numerous studies on intermittent fasting and has found that 90 percent of the weight people lose is body fat, with only 10 percent being lean body mass.6 Moving throughout the day and consuming an appropriate amount of high-quality protein will help minimize loss of muscle mass.
The 5:2 Intermittent Fasting Plan
Intermittent fasting is an umbrella term that covers a wide array of fasting schedules. As a general rule, it involves cutting calories in whole or in part, either a couple of days per week, every other day, or even daily. Dr. Michael Mosley became so convinced of the health benefits of intermittent fasting that he wrote a book on the subject, The Fast Diet: Lose Weight, Stay Healthy, and Live Longer with the Simple Secret of Intermittent Fasting.7
The fasting schedule he suggests is to eat normally for five days per week, then fast for two, which is referred to as the 5:2 intermittent fasting plan. On fasting days, he recommends cutting your food down to one-fourth of your normal daily caloric intake, or about 600 calories for men and about 500 for women, along with plenty of water and tea. Dr. Mosley reports having lost 19 pounds in two months by following this 5:2 intermittent fasting plan.
It really doesn't matter which days you choose as your fasting days. Monday is a good place to start if you're fired up at the beginning of a new week or if you've had a "calorific" weekend. On a fasting day, you can spread your 500/600 calories throughout the day, or you might choose to enjoy them all at an evening meal. Just find the routine that works best for you. Dr. Mosley offers three "golden rules" for success:8
- Be sensible on non-fasting days. Eat normally, enjoy treats in moderation, but avoid bingeing.
- Watch what you drink. Juices, lattes, alcohol, fizzy drinks, and smoothies typically contain a glut of calories and sugar but won't satisfy your appetite.
- Try adding another fasting day. Go for a 4:3 pattern (four days of normal eating, three days of reduced calories). Or even use alternate-day fasting, which can really bump up your weight loss over the course of a few months, especially if you exercise.
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My Personal Recommendations
The version of intermittent fasting that I recommend for nearly anyone with insulin resistance is simply to restrict your eating to a specific window of time every day, such as an eight-hour window. I have experimented with different schedules for the past three years, and this is my personal preference as it's really easy to comply with once your body has made the shift from burning sugar to burning fat for its primary fuel. Fat, being a slow-burning fuel, allows you to keep going without suffering from the dramatic energy crashes associated with sugar. And if you're not hungry, then not eating for several hours is no big deal!
You do this every day until your insulin/leptin resistance improves and your health issues resolve, such as suboptimal weight, blood pressure, blood sugar, etc. After that, just do it as often as you need to maintain your healthy state. I initially used a six-hour eating window, but now I use a 10- to 11-hour window, and I rarely eat anything during the four hours prior to going to bed. I disagree with claims that you can eat whatever you want on non-fasting days. If your goal is optimal health (not just weight loss), you simply cannot achieve this without a high-quality diet. In terms of what to eat on non-fasting days, I recommend following these five basic guidelines:
- Avoid junk food, processed food, and sugar-laden drinks
- Limit your fruit consumption until your weight and health have normalized, especially fruits high in fructose
- Replace starchy, carbohydrate-rich foods with healthy fats such as coconut oil, olive oil, olives, butter, eggs, avocados, and nuts (macadamia nuts are particularly beneficial, as they are high in fat and low in protein)
- Consume protein moderately, making sure your animal products (meat, eggs, dairy) come from organic, pasture-raised animals
- Include naturally fermented foods (fermented vegetables, yogurt, kefir, miso, etc.) in your diet, which are extremely beneficial for your digestive tract, immune system, and just about every other aspect of your health
Tapping Away Your Anxiety About Fasting—FAST
Compliance is a critical factor for any intermittent fasting plan, regardless of which schedule you're trying to implement, and stress about fasting can sabotage your success. You can't address your physical health without also addressing your mental health because the connection between your mind and body is undeniable. Does the very thought of fasting trigger anxiety for you? If so, you're not alone.
EFT makes it possible to tap away your anxiety about fasting—it's one of the most powerful tools for reducing stress and anxiety that I know of. In 2012, a triple blind study9 found that EFT reduced cortisol levels and symptoms of psychological distress by 24 percent—more than any other intervention tested.
Do you worry you'll be hungry all the time? Are you afraid you'll feel deprived or suffer unbearable cravings? Are you worried it won't work for you? Julie covers all of these common issues in her video—and more. The first few weeks of fasting are typically the most challenging, while your body is making the necessary biochemical adjustments to its metabolic engine. Tapping can be extraordinarily beneficial for eliminating anxiety and cravings during this time. EFT is easy to learn and once you do, it's always at your fingertips—whenever and wherever you need it.
Who Should Use Extra Caution When Fasting, or Avoid It Altogether?
Intermittent fasting is appropriate for most people, but there are certain individuals who should exercise some extra caution. If you fall into any of the following five categories, my recommendation would be to focus on improving your overall nutrition instead of implementing a fasting schedule.
- Severe chronic stress (adrenal fatigue)
- Cortisol dysregulation
- Pregnant or nursing mothers
Hypoglycemia is a condition characterized by tendencies toward abnormally low blood sugar. It's commonly associated with diabetes, but you can be hypoglycemic even if you're not diabetic. Common symptoms of a hypoglycemic crash include headache, weakness, tremors, irritability, and hunger. As your blood glucose levels continue to plummet, more severe symptoms can set in, such as confusion or abnormal behavior, visual disturbances, seizures, and loss of consciousness.
One of the keys to preventing hypoglycemia is eliminating excess sugars (especially processed fructose) and grains from your diet, and replacing them with high-quality proteins and fats. Keep in mind that it will take some time for your blood sugar to normalize. If you're prone to hypoglycemia, instead of fasting, just work on optimizing your overall diet until your blood sugar levels are stable. Once you've achieved this, then you can gradually begin experimenting with fasting. Pregnant or nursing mothers should avoid fasting, as there is no research thus far to support its benefit.
Your baby needs plenty of nutrients, during and after birth. If you're pregnant, make sure to include naturally fermented foods to optimize your and your baby's gut flora. For more information about this, please listen to my interview with Dr. Natasha Campbell-McBride. If you have chronically elevated stress, then chances are your cortisol is dysregulated. Chronic stress can inflict severe long-term damage to your health, so it's imperative that you find a way to manage it. The good news is, you now have EFT—one of the most effective tools out there for managing stress.